The present invention relates to an radiant heated-water boiler and in particular to an improved heat exchanger therefor.
In prior, U.S. Pat. No. 4,442,799, of which the prsent applicant is a co-inventor, a radiant heated-water boiler is disclosed having a heat exchanger comprising a cylindrical shell, in which a gas fired combustion element is concentrically disposed. The combustion element is connected to a heat source, such as a gas/air mixture, which ignites the combustion element, the ignited gases passing through the element into the surrounding hollow shell. Disposed at a clearance position, about the combustion element is a helically coiled tube, through which water is pumped, which water thus absorbs the heat from the combustion element.
While this construction is highly effective and more efficient than those heat exchange arrangements previously known, several disadvantages have become known. For example, the use of a helically coiled tube increases the cost of the heat exchanger due to its complexity, labor intensiveness, and cost of basic raw material, such as the copper needed for the tube. In addition, the exchange of heat is based solely on radiation and convection impinging on the tube to heat the water in the tube. Further, only a limited through-put of water is possible, since the water had to pass serially through the spiral tube.
It is an object of the present invention to provide a heat exchanger for use in a radiant heated-water boiler which is simpler in construction than those known heretofor and which provides improved efficiency in operation.
It is a particular object of the present invention to provide a heat exchanger for use in radiant heated-water boilers in which heat transfer is effective by conduction as well as by convection.
These objects as well as other objects, features and advantages will be more fully appreciated from the following disclosure of the presently preferred but nevertheless illustrated embodiments.